H-protein of glycine decarboxylase is encoded by multigene families in Flaveria pringlei and F. cronquistii (Asteraceae).

In Flaveria pringlei and F. cronquistii unlike other plants, H-protein of the glycine cleavage system is encoded by small multigene families. From leaf cDNA libraries and by reverse transcription of mRNA with subsequent polymerase chain reaction (PCR) amplification, we have obtained three different H-protein cDNA clones from each species. The relative levels of total H-protein mRNA, as well as of different H-protein transcripts, have been determined in leaves, stems, and roots of F. pringlei. Stems, with a total of 22% relative to leaves, contain substantial amounts of H-protein transcripts. The corresponding level in roots is relatively low (2.3% relative to leaves) but easily detectable. One of the transcripts occurs only in leaves (HFP20) and another one (HFP13) is present exclusively in photosynthesizing organs. Only one of the H-protein transcripts (HFP4) was found in all three organs, in leaves, stems, and roots of F. pringlei.